The Androgen Dehydroepiandrosterone Sulfate Shows a Greater Relationship with Impulsivity than Testosterone in a Healthy Male Sample.

This study was designed to examine the relationships among the impulsivity construct as a personality trait, the dehydroepiandrosterone sulfate (DHEA-S), and testosterone in a sample of 120 healthy middle-aged males (Mage = 44.39; SD = 12.88). The sum of the three BIS-11 scales, the SR, and the five UPPS-P scales correlated with DHEA-S 0.23 (p < 0.006) and testosterone 0.19 (p < 0.04), controlling for age. Partial correlations showed that DHEA-S was significantly related to motor impulsivity (0.24; p < 0.008), Sensitivity to Reward (0.29; p < 0.002), Lack of Premeditation (0.26; p < 0.05), and, to a lesser extent, Sensation Seeking (0.19; p < 0.04) and Positive Urgency (0.19; p < 0.04). Testosterone correlated with attention impulsivity (0.18; p < 0.04), Sensation Seeking (0.18; p < 0.04), and Positive Urgency (0.22; p < 0.01). Sensitivity to Reward, Negative Urgency, and Positive Urgency were significant predictors of DHEA-S (R2 = 0.28), and Positive Urgency for testosterone (R2 = 0.09). Non-parametric LOESS graphical analyses for local regression allowed us to visualize the non-linear relationships between the impulsivity scales with the two androgens, including non-significant trends. We discuss the implications of these results for impulsive biological personality traits, the limitations of our analyses, and the possible development of future research.

Convergence of the dimensional assessment of personality pathology (DAPP-BQ) and the five-factor personality inventory for the international classification of diseases 11th edition (FFiCD) in the context of the five-factor model and personality disorders.

The current manuscript presents the convergence of the Dimensional Assessment of Personality Pathology (DAPP-BQ), using its short form the DAPP-90, and the Five-Factor Personality Inventory for International Classification of Diseases (ICD-11), the FFiCD, in the context of the five-factor personality model and the categorical approach of personality disorders (PDs). The current manuscript compares the predictive validity of both the FFiCD and the DAPP-90 regarding personality disorder scales and clusters. Results demonstrate a very high and meaningful convergence between the DAPP-90 and the FFiCD personality pathology models and a strong alignment with the FFM. The DAPP-90 and the FFiCD also present an almost identical predictive power of PDs. The DAPP-90 accounts for between 18% and 47%, and the FFiCD between 21% and 47% of PDs adjusted variance. It is concluded that both DAPP-90 and FFiCD questionnaires measure strongly similar pathological personality traits that could be described within the frame of the FFM. Additionally, both questionnaires predict a very similar percentage of the variance of personality disorders.

Prefrontal activity during IOWA Gambling Task in young adult women.

This study aims to investigate the relationships between personality traits of impulsivity, using the UPPS-P Impulsive Behaviour Scales shortened version, and prefrontal cortex (PFC) activity during the IOWA Gambling Task (IGT) in young adult women. The study included a sample of 83 young, healthy females (19.8 ± 1.4 years), who voluntarily took part in the study. Repeated measures analysis during the IGT revealed a significant increase in HbO (all p <.001; ηp2 >.31) and a decrease in Hbr (all p <.003; ηp2 >.08) in all prefrontal quadrants. This increase in oxygenation occurs primarily during the choice period under ambiguity (r =.23; p =.039). Additionally, there was a significant linear decrease in selecting the decks associated with a high frequency of losses (p <.001), while the favorable deck with low losses showed a linear increase (F = 12.96; p <.001). Notably, discrepancies were found between UPPS-P and IGT impulsivity ratings. The Lack of Perseverance and Lack of Premeditation scales from the UPPS-P were identified as significant predictors of HbO levels, mainly in the two quadrants of the left hemisphere's, lateral (adjusted R2 =.23; p <.001; f2 =.34) and rostral (adjusted R2 =.13; p <.002; f2 =.17). These findings suggest that young adult women predominantly adopt a punishment-avoidance strategy during IGT, exhibiting increased activation in the left hemisphere, especially during the task's initial phase characterized by ambiguity.

Psychological predictors of risky driving: the role of age, gender, personality traits (Zuckerman's and Gray's models), and decision-making styles.

The present study was planned to study the relationships between age, personality (according to Zuckerman's and Gray's psychobiological models) and decision-making styles in relation to risky driving behaviors. The participants were habitual drivers, 538 (54.3%) men and 453 (45.7%) women, with a mean age around 45 years and mainly of middle socioeconomic status. The results indicate that the youngest men and women reported more Lapses, Ordinary violations, and Aggressive violations than the oldest men and women. Women reported more Lapses (d = -0.40), and men more Ordinary (d = 0.33) and Aggressive violations (d = 0.28) when driving. Linear and non-linear analysis clearly support the role of both personality traits and decision-making styles in risky driving behaviors. Aggressiveness, Sensitivity to Reward, Sensation Seeking played the main role from personality traits, and Spontaneous and Rational decision-making style also accounted for some variance regarding risky driving behaviors. This pattern was broadly replicated in both genders. The discussion section analyses congruencies with previous literature and makes recommendations on the grounds of observed results.

Decision-Making and the Alternative Five Factor Personality Model: Exploring the Role of Personality Traits, Age, Sex and Social Position.

This study explores the relationship between decision-making style, as measured by the Melbourne Decision Making Questionnaire, and personality based on alternative five-factor model along with effect of age, sex and social position on such styles. A large sample of community and undergraduate students (n = 1,562; Mage = 40.03, SD = 18.43) was analyzed. The results showed that Neuroticism and Extraversion were significantly related to the non-vigilant styles Hypervigilance, Buck-passing and Procrastination. Women scored significantly lower in Vigilance and higher in Hypervigilance, Buck-passing and Procrastinations than men. Age was significantly related to decision-making style in a U-shaped fashion. The Social Position Index was significantly related to all decision-making styles. The most predictive personality domains regarding decision-making scales were Aggressiveness (negatively) and Activity for Vigilance, and Neuroticism for Hypervigilance, Buck-passing and Procrastination. Age, sex and social position had a small/medium overall effect on the four dimensions of Melbourne Decision Making Questionnaire (p < 0.001) with a η2 of 0.038, 0.068, 0.050, and 0.031 for Vigilance, Hypervigilance, Buck-passing and Procrastination, respectively. Based on scores on a single factor dimension of the MDMQ, the profile of participants with higher scores was characterized by lower age, more likely to be females, lower social position, higher levels of Aggressiveness, less Activity, less Extraversion, and higher Neuroticism.

Biological correlates of the Toronto Alexithymia Scale (TAS-20) in cardiovascular disease and healthy community subjects.

This research studies the relationship between Alexithymia, behavioural, biometric, biochemical and cardiovascular risk in clinical and healthy samples. There were 602 participants (mean age of 52.82 ± 10.59) divided into two groups. The first was made up of 202 patients (165 males and 37 females) who had suffered a cardiovascular disease (CVD), while the second was composed of 400 (285 males and 115 females) healthy volunteers without CVD diagnosis. A cardiovascular risk index (CRI) was developed with the high factorial loading of the following variables: systolic and diastolic blood pressure, total cholesterol/HDL, triglycerides, body mass index, glucose and alcohol and tobacco consumption. The results showed a significant correlation between Alexithymia and the CRI. After controlling for age, sex, occupation, alcohol and tobacco consumption, this correlation decreased, but remained significant for most values. Alexithymia predicted 6% of CRI in the entire sample, once age and sex effect were discounted. Alexithymic subjects with scores above a cut-off point set at higher than 60 had higher levels of glucose, systolic, diastolic, cholesterol/HDL and cardiovascular risk. We discuss that Alexithymia scores contribute to cardiovascular risk, supporting previous findings.

Differences in prefrontal cortex activity based on difficulty in a working memory task using near-infrared spectroscopy.

The Prefrontal cortex (PFC) has been highly related to executive functions such as working memory (WM). This study assesses the activity of the PFC in performing the Sternberg WM task (ST) with three levels of difficulty (easy, medium and hard) using the near-infrared spectroscopy (fNIRS) technique. Participants were 43 young and healthy right-handed women. Nine WM task blocks were pseudo randomly presented, three for each difficulty task. The results showed that the participant's performance was better in the easy trials than in the medium and hard trials. Performance in the medium trials was also better than in the hard ones. Bonferroni-corrected paired post-hoc t-tests indicated higher oxygenation in medium and hard tasks than in the easy ones for times between 13 and 42 s in the left lateral PFC and in both, medial and lateral, right PFC. Significant differences in Oxygenated hemoglobin (HbO), Total hemoglobin (HbT) and oxygenation (Oxy) changes depending on the Sternberg WM task were found. Unlike previous studies with fNIRS and WM, the current study uses a highly controlled WM task that differentiates between encoding, retention and retrieval phases, comparing different levels of task load.

Startle reflex modulation by affective face "Emoji" pictographs.

The current research was designed to assess possible differences in the emotional content of pleasant and unpleasant face emoji using acoustically evoked eyeblink startle reflex response. Stimuli were selected from Emojipedia Webpage. First, we assessed these stimuli with a previous independent sample of 190 undergraduate students (46 males and 144 females) mean age of 21.43 years (SD 3.89). A principal axis method was performed using the 30 selected emoji faces, extracting two factors (15 pleasant and 15 unpleasant emoji). Second, we measured the acoustic startle reflex modulation in 53 young adult women [mean age 22.13 years (SD 4.3)] during the viewing of each of the 30 emoji emotional faces in the context of the theory of motivation and emotion proposed by Lang (1995), but considering only the valence dimension. We expected to find higher acoustically evoked startle responses when viewing unpleasant emoji and lower responses for pleasant ones, similarly to the results obtained in the studies using human faces as emotional stimulus. An ANOVA was conducted to compare acoustic startle responses associated with pleasant and unpleasant emoji. Results yielded main effects for picture valence (λ = 0.80, F(1, 50) = 12.80, p = .001, η2 = 0.20). Post-hoc t test analysis indicated significant differences in the startle response between unpleasant (50.95 ± 1.75) and pleasant (49.14 ± 2.49) emoji (t (52) = 3.59, p = .001), with a Cohen's d = 0.495. Viewing affective facial emoji expressions modulates the acoustic startle reflex response according to their emotional content.

Prefrontal cortex activity triggered by affective faces exposure and its relationship with neuroticism.

The emotional processing of affective faces is an essential element of social relationships. Individual differences in personality traits such as neuroticism can influence how we manage these interactions. The objective of this study was to analyze changes in prefrontal cortex (PFC) activity in response to visual exposure to affective faces, and to ascertain whether changes in PFC activity were related to scores in neuroticism, including depression, anxiety, low self-esteem and dependence facets. Fifty-two healthy undergraduate female students participated in the present study. Results showed significant differences depending on face valence in the left and right ventrolateral PFC. We found a reduction in oxygen consumption in reaction to neutral and happy faces, and a small increase in oxygenation in reaction to angry faces both in the left and the right PFC. There were significant positive correlations in the left ventrolateral PFC between oxygenation changes during exposure to neutral and happy faces and the neuroticism factor. Anxiety and depression facets showed positive significant correlations with oxygenation changes for all Time blocks. Notice that participants with high neuroticism scores did not show differences in ventrolateral PFC activity depending on face valence. We suggest that PFC would play a protective role in response to emotional stimuli. The reduced regulatory control of PFC over the amygdala could explain vulnerability to emotional disorders in subjects with high neuroticism.

Neuroticism is associated with reduced oxygenation levels in the lateral prefrontal cortex following exposure to unpleasant images.

The aim of this study was to explore the prefrontal cortex response to emotional salient stimuli in subjects with high scores in Neuroticism (and low in Sensation Seeking) or high scores in Sensation Seeking (and low in Neuroticism) personality traits, -called now Neuroticism and Sensation Seeking groups-. For this purpose, we selected 24 females (mean age: 20; SD: 1.74 years) and assigned them to two different groups according to their extreme score in personality dimensions. Ten pleasant and ten unpleasant pictures from the International Affective Picture System were presented. Neuroticism group showed significant effects for valence at the lateral prefrontal cortex in both brain hemispheres. They showed higher Oxygenation for pleasant pictures, more significantly in the left (Z = 2.49, p = 0.01) than in the right hemisphere (Z = 2.19, p = 0.03). The highest differences were registered in ventral optodes. In contrast, Sensation Seeking group did not show significant differences in hemodynamic variables as depending on the valence of the pictures. These data suggest a differential functioning of the lateral prefrontal cortex, mainly the left ventrolateral cortex, in Neuroticism group to pleasant and unpleasant visual stimuli. We hypothesize that if the lateral prefrontal activity is low, it could be the result of an over-activation of the amygdala in response to unpleasant pictures in subjects with Neuroticism or negative emotionality. These activation patterns could be related to vulnerability to emotional disorders.

Sex differences and personality in the modulation of the acoustic startle reflex.

The modulation of the eyeblink component of the acoustic startle reflex (ASR) has been used to study human motivation, attention, and emotion towards affective stimuli of different valence. However, sex and individual differences in personality have been rather overlooked concerning the change in the ASR to brief affective sequences. In this study, we aimed to evaluate sex differences in the ASR, together with the influence of sensitivity to punishment (SP) and sensitivity to reward (SR) in the affective modulation of the ASR to pleasant and unpleasant pictures. We addressed this topic with a latent curve model (LCM) representing the change in the ASR of an extensive group of men (n = 166) and women (n = 109). There was a significant habituation of the ASR to the pleasant pictures, and a significant sensitization of the ASR to the unpleasant pictures. Both effects were higher and more variable for women than for men. There were in addition interactive and quadratic effects of SP and SR on the ASR to the pleasant and unpleasant pictures. Men and women with extreme scores in SP, and women with low scores in SR habituated faster to the pleasant stimuli. For men scoring low in SP, higher scores in SR related with an attenuated initial ASR to the unpleasant stimuli. Women with extreme scores in SP had a higher initial ASR to the unpleasant stimuli. There were remarkable asymmetries between men and women concerning personality effects on the change in the ASR to affective stimuli.

Examining habituation of the startle reflex with the reinforcement sensitivity theory of personality.

The habituation of the acoustic startle reflex (ASR) was examined concerning individual differences in sensitivity to punishment (PUN) and sensitivity to reward (REW), within the general framework of the reinforcement sensitivity theory (RST) of personality. Two hypotheses derived from the RST were evaluated: the separable subsystems hypothesis and the joint subsystems hypothesis. In addition, we examined the direction of the relationship of PUN and REW with the habituation of the ASR. A habituation segment of electromyography recordings of the orbicularis oculi was assessed with an unconditional latent curve model. In accordance with the RST hypotheses, the relationship of PUN and REW on the habituation process was assessed with two conditional latent curve models. There was higher support for the separable subsystems hypothesis. In addition, PUN and REW related with the habituation trajectory of the ASR in the expected directions. Higher levels of PUN and lower levels of REW related with a slower habituation of the ASR, whereas lower levels of PUN and higher levels of REW related with a faster habituation of the ASR.

The Dimensional Assessment of Personality Psychopathology Basic Questionnaire: shortened versions item analysis.

This study has been designed to evaluate and replicate the psychometric properties of the Dimensional Assessment of Personality Psychopathology-Basic Questionnaire (DAPP-BQ) and the DAPP-BQ short form (DAPP-SF) in a large Spanish general population sample. Additionally, we have generated a reduced form called DAPP-90, using a strategy based on a structural equation modeling (SEM) methodology in two independent samples, a calibration and a validation sample. The DAPP-90 scales obtained a more satisfactory fit on SEM adjustment values (average: TLI > .97 and RMSEA < .04) respect to full DAPP-BQ and the 136-item version. According to the factorial congruency coefficients, the DAPP-90 obtains a similar structure to the DAPP-BQ and the DAPP-SF. The DAPP-90 internal consistency is acceptable, with a Cronbach's alpha mean of .75. We did not find any differences in the pattern of relations between the two DAPP-BQ shortened versions and the SCL-90-R factors. The new 90-items version is especially useful when it is difficult to use the long version for diverse reasons, such as the assessment of patients in hospital consultation or in brief psychological assessments.

Affective modulation of the startle reflex and the Reinforcement Sensitivity Theory of personality: The role of sensitivity to reward.

This study evaluated differences in the amplitude of startle reflex and Sensitivity to Reward (SR) and Sensitivity to Punishment (SP) personality variables of the Reinforcement Sensitivity Theory (RST). We hypothesized that subjects with higher scores in SR would obtain a higher startle reflex when exposed to pleasant pictures than lower scores, while higher scores in SP would obtain a higher startle reflex when exposed to unpleasant pictures than subjects with lower scores in this dimension. The sample consisted of 112 healthy female undergraduate psychology students. Personality was assessed using the short version of the Sensitivity to Punishment and Sensitivity Reward Questionnaire (SPSRQ). Laboratory anxiety was controlled by the State Anxiety Inventory. The startle blink reflex was recorded electromyographically (EMG) from the right orbicularis oculi muscle as a response to the International Affective Picture System (IAPS) pleasant, neutral and unpleasant pictures. Subjects higher in SR obtained a significant higher startle reflex response in pleasant pictures than lower scorers (48.48 vs 46.28, p<0.012). Subjects with higher scores in SP showed a light tendency of higher startle responses in unpleasant pictures in a non-parametric local regression graphical analysis (LOESS). The findings shed light on the relationships among the impulsive-disinhibited personality, including sensitivity to reward and emotions evoked through pictures of emotional content.

Habituation in acoustic startle reflex: individual differences in personality.

This study analyzed the relationship of individual differences in personality with habituation in the acoustic startle response (ASR). Data from nine trials in ASR to white noise bursts and a personality questionnaire based on the alternative big five personality approach were modelled with a latent growth curve (LCM) including intercept and slope habituation growth factors. There was a negative correlation between the intercept and slope, indicating that individuals with higher initial ASR levels had also a more pronounced and faster decrease in the ASR. Contrary to expectations, Extraversion and Sensation Seeking did not relate with habituation in ASR. Neuroticism and Aggressiveness related asymmetrically with the habituation rate in ASR. Higher levels of Neuroticism were related with faster habituation, whereas higher levels of Aggressiveness were related with slower habituation. Further studies with the LCM should be undertaken to clarify in a greater extent the association of personality with habituation in ASR.

Normal personality versus pathological personality: dimensional and predictive study.

The present study aimed to replicate the previous relationship between the Zuckerman personality model and the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ) and to evaluate the contribution of the facets and factors from Zuckerman's new instrument Zuckerman-Kuhlman-Aluja Personality Questionnaire (ZKA-PQ) versus the old Zuckerman-Kuhlman Personality Questionnaire to the four clusters of the DAPP-BQ. The sample consisted of 443 subjects from the general population of both sexes. The ZKA-PQ dimensions predicted between 35 % and 61% of the DAPP-BQ cluster variance and facets between 54% and 63%. Local regression graphical analysis (LOESS) showed that neuroticism and aggressiveness are the dimensions most related with emotional dysregulation. Sensation seeking and aggressiveness were associated with dissocial behaviour. Neuroticism and extraversion (negative) were associated with social avoidance and activity and sensation seeking (negative) with compulsiveness. The new ZKA-PQ improves the psychometric properties of the old Zuckerman-Kuhlman Personality Questionnaire. Both dimensional personality measures can play a role in the prediction of the future DSM-V personality disorder dimensional system.

Presentation and AcqKnowledge: an application of software to study human emotions and individual differences.

This work describes an experiment about startle reflex and individual differences in personality with the application of the Presentation and AcqKnowledge software. First, Presentation was useful for the design of the display and timing of a set of pictures from the IAPS (International Affective Picture System) that modulated the elicitation of the startle reflex response to an acoustic stimulus. Second, the AcqKnowledge program allowed to record and store psychophysiological data, while a Java routine helped to transform the output data into a proper data disposition better suited to analyze individual differences. The software used in psychophysiological experiments is of an utmost importance concerning the design and presentation of stimuli, and to the general management of this type of information. In this work, we present an example of the use of two computer programs that are helpful for the research about the psychophysiological bases of individual differences in relation with human personality, even though they are extensible to other biomedical areas of interest.

Effects of adult dysthyroidism on the morphology of hippocampal granular cells in rats.

Thyroid hormones are essential for normal brain development and very important in the normal functioning of the brain. Thyroid hormones action in the adult brain has not been widely studied. The effects of adult hyperthyroidism are not as well understood as adult hypothyroidism, mainly in hippocampal granular cells. The purpose of the present study is to assess the consequences of adult hormone dysthyroidism (excess/deficiency of TH) on the morphology of dentate granule cells in the hippocampus by performing a quantitative study of dendritic arborizations and dendritic spines using Golgi impregnated material. Hypo-and hyperthyroidism were induced in rats by adding 0.02 percent methimazole and 1 percent L-thyroxine, respectively, to drinking water from 40 days of age. At 89 days, the animals' brains were removed and stained by a modified Golgi method and blood samples were collected in order to measure T4 serum levels. Neurons were selected and drawn using a camera lucida. Our results show that both methimazole and thyroxine treatment affect granule cell morphology. Treatments provoke alterations in the same direction, namely, reduction of certain dendritic-branching parameters that are more evident in the methimazole than in the thyroxine group. We also observe a decrease in spine density in both the methimazole and thyroxine groups.

Effects of adult dysthyroidism on the morphology of hippocampal neurons.

This study investigates the effect of thyroid hormones on the morphology of hippocampal neurons in adult rats. Hypo- and hyperthyroidism were induced by adding 0.02% methimazole and 1% l-thyroxine, in drinking water from 40 days of age, respectively. When the rats were 89 days old their brains were removed and stained by a modified Golgi method and blood samples were collected in order to measure T4 serum levels. Neurons were selected and drawn using a camera lucida. Our results show that methimazole administration reduces the dendritic branching of the apical shafts of CA3 and CA1 pyramidal neurons mainly by increasing the distance to the first branch point in both types of neurons, and reducing branch points in the radius of 50 microm from the soma in CA1 neurons. Nevertheless, it was observed an increase of apical spine density in CA3 neurons from this group. Thyroxine reduces apical and basal tree of CA3 pyramidal neurons increasing the distance to the first branch point, reducing branch points in the radius of 50 microm from the soma and increases their apical and basal spine density. In CA1 field, thyroxine reduces the number of basal branch points. Both treatments seems to provoke alterations in the same direction reducing the dendritic branching and increasing spine density, although no significances appeared in some of the parameters analyzed. The effects are more evident in thyroxine than methimazole group; and in CA3 neurons than in CA1 neurons. In discussion it is pointed that the increase of spine density could be a mechanism to compensate the functionality reduction that can be provoke by the treatment effect on dendritic branching.

Perinatal hypothyroidism effects on step-through passive avoidance task in rats.

Previous studies have documented a decrease in the ability of neonatal hypothyroid animals to learn and habituate to maze tests, and an increase in spontaneous activity. However, there is little information about the effects of perinatal (i.e., prenatal and postnatal) hypothyroidism on behaviour. The present study was designed to assess whether perinatal hypothyroidism in rats induces alteration on acquisition and/or short- and long-term retention of a learned response in male Wistar rats. Perinatal hypothyroidism was induced by prolonged (E9-P21) exposure of pregnant and lactating dams to methimazole (administered orally in drinking water, 0.2 mg/ml). Cognitive function was tested at 50 days by means of a step-through passive avoidance task. The effects of perinatal hypothyroidism on the retention of the passive avoidance response are long lasting being, however, highly dependent on the retention after the original training. Our results showed that methimazole-treated rats performed more poorly when retention was tested at long-term (24 h and 7 days) retention interval. Instead, methimazole-treated rats showed longer retrieval latencies than the control ones did when retention was tested at short term (1 h).